Brush and brush material



1945- R. o. PETERSON 88,867

BRUSH AND BRUSH MATERIAL Filed March 23, 1942 LTan INVENTOR. v RUBEN O. PETERSON M,,(Mv 9 H Trek/way;

atente Nov. l3, l

BRUSH AND BRUSH MATERIAL Ruben 0. Peterson, Elevelandl, Ulric, assignor to Ellie Osborn Manufacturing Company, illeve= land, Ohio, a corporation oi Ohio Application March 23, 1M2, Serial No. 435,853

4 Claims. '(Cl. 300-211.)

This invention relates as indicated to new and improved brushes and brush materiaLand more particularly to rotary brushes which have been specially treated to render the same more emcient.

Cleaning, polishing and shaping of manufactures of many forms have long been done by means of various abrasives applied by rotary brushes. A variety of brush materials is empioyed in such brushes, including certain vegetable fibers of which Tampico fiber may be taken as the most common example.

Numerous difficulties have been encountered in commercial practice. Due to the high speed of the brushes, often in excess of 3000 R. P. M., there is considerable flexing and rubbing of the bristles which generates heat sumcient to scorch the fiber and also tends to break it off adjacent the brush back. This tendency is accentuated when abrasive materials are supplied to the brush for application to the work since the increase of work done increases the generation of destructive heat and also such abrasives work down between the fibers and are more free to cut the same when fluttering and flexing is unrestrained. Furthermore, as the abrasives do not generally adhere well to the brush material, a considerable proportion of the abrasive is wasted. It has also been found that the brush material in annular rotary brushes of the usual type tends to compact axially at the outer periphery of the brush when such brush is rotating at high speeds. This means that no matter how carefully the brush may have been trimmed to provide an absolutely fiat periphery the brush in use will so shape itself as to make a v or notched cut in the work. It also means that a shorter length of fiber and reduced brush life is necessary to achieve a given effect if the movement of the fibers relative to one another is to be left unrestrained.

It is, therefore, a primary object of this invention to provide a treatment for brushes of the above defined type which will considerably increase the life of such brushes.

. A further object of this invention is to provide improved brush material of greatly increased eff-ectiveness in the application of abrasive materials to the work.

Still another object is to protect the brush fibers from the softening efiect of contacting materia such as warm aqueous solutions.

Other objects of this invention will appear as the description proceeds.

To the accomplishment of the foregoing and related ends, said invention, then, consists of the means hereinafter fully described and particularly pointed out in the claims.

The annexed drawing and the following description set forth in detail certain structure embodying the invention, such disclosed means constituting, however, but one of various structural forms in which the principle of the invention may be used.

In said annexed drawing:

Fig. l is a side elevational view of a typical annular rotary brush section;

Fig.2 is a sectional view of such brush taken along the line 2-1 on Fig. 1 while rotating at operational speed;

Fig. 3 is a similar sectional view but showing the effect on such brush of the treatment of this invention; and

Fig. l is a sectional view taken through a block of plastic which has been acted upon by the brushes of Fig. 2 and Fig. 3 respectively, and

showing the effect on the work-piece of treatment of the brush in accordance with my invention.

Referring now more particularly to such'drawing, the rotary brush section there illustrated ance with the teaching of application Serial No.

281,068, new Patent No. 2,288,337, June 30, 1942, of William S. Whittle. Although a brush formed as above described may have brush material which actually flares somewhat as it emerges from the channelform brush back, it is obvious that such material will be more densely compacted in the brushback than at its outer periphery. It is therefore possible to compress the brush material adjacent the outer periphery into a relatively thin layer. When the brush is mounted on a mandrel and rotated at high operational speed it isfound that the brush material of its own accord assumes the position indicated in Fig. 2. This is believed to be due largely to the flow of air which is forced out radially due to centrifugal force. When such brush is applied to a block of a common commercial synthetic plastic 4, for example. it will be found to make a rather V-shapecl notch 5 in such block. This of course means that a uniform cutting or polishing action is not being obtained, and is often highly undesirable.

I have found that if such brush material be treated with a viscid tacky oil the bristles will maintain their proper positions, as shown in Fig. 3, and the brush will give an ideal fiat cut 8 in the work-piece 4.

Such treatment also adds tothe life of the brush material, by lubricating the same, dampening vibration, and restricting undesirable and destructive fiber movement without eliminating the desirable amount of movement. Larger .quantities of abrasive materials can be carried and such abrasives will be substantially concentrated at the working periphery of the brush where they are most eflective.

The material selected for treating the brush material should have the following characteristics:

It must wet (i. e. directly coat) the bristles so as to be retained thereon and-have a high viscosity, since too free-flowing fluids are quickly thrown off by the rapidly rotating brush under the influence of centrifugal force. This latter limitation applies to the treated brush ready for use and not necessarily to the treating material at the time of treatment as such material may then be. diluted with a solvent as explained below. 'The treating material should also be sufflciently tacky to have a restraining influence on the bristles, therebycausing proper spacing of the same and minimizing compacting without preventing them from opening or separating as needed for the passage of small portions of or projections on the article being brushed. Thus, if the treated bristles be pulled apart they will return to their original positions and again adhere.

not be employed, on the other hand, which solid-,

ify into hard and brittle substances incapable of any yielding action but will be selected to retain the desired degree of tackiness or plasticity in use.

It is additionally desirable: that the treating material employed be of a type which is readily removable from the work-piece. The selection fore depend on whether a metal, synthetic plastic, orv other surface is to be acted upon.

I have found that the various semi-drying oils, such as soya bean oil and blown hemp seed oil, both with and without the addition of alkyd resins or similar agentsfare generally suitable for use in accordance with my invention. Tung oil, on the other hand, in the form commercially available, is not suitable, and linseed oil will generally be avoided as being too drying and pro.- moting spontaneous combustion. A- commercially available composition which has been found very suitable for use as a tack increasing ingredient in accordance with my invention is a polymerized petroleum fraction sold under the trade name of Vistanex. This material, while very tacky and otherwise suitable, may beeasily removed from the workpiece by washing with a petroleum fraction.

The following is a list of various examples of oils which serve to illustrate the type of composition which may be employed in accordance with my invention:

1. Boys bean oil 3. Boys bean oil with additions of alkyd resins and tack additives such as Vistanex" 4. "Vistanex" 5. Hemp seed oil and combinations of same as in case of soya bean oil mentioned above 6. Castor oil,, especially that form which is petroleum fraction soluble, and combinations of same as in case of soya bean oil 'l. Perilla oil and combinations of same as in case 11. Soaps, especially those that have considerable I tack such as zinc and iron soaps It will be noted that the above oils, while quite viscous and sticky, do not tend to harden quickly or become brittle so that the treated brush will retain its desired characteristics for a very considerable period of time.

Penetration of the treating oils and compounds into and among the brush fibers is facilitated by the use of a proper amount and quality of solvent which may later be removed by evaporation. Thesemay be added as needed to any of the oils mentioned. Typical solvents employedare Stoddards Solvent and DuPonts 3825 Automotive Thinner" (a mixture largely consisting of a pctroleum fraction, alcohol, and minor amount of certain coal tar derivatives).

Typical examples of the alkyd resins above referred to which are suitable for use in accordance with my invention may be selected from the glycerine phthalate condensation products, such as the Dulux Resin marketed by DuPont;

'of the particular material employed may there- I While the treatment of this invention is applicable to stranded or filamental brush material generally, certain types of material are particularly suited therefor. In addition to Tampico fiber mentioned above, horse-hair and various types of twisted and braided cord have been employed with excellent results. An unusual development has been in the use of certain types of wire brushes and brushes utilizing a mixture of wire and horse-hair or wire and Tampico fiber. The ordinary wire brush employing the smaller gauges of. wire has required crimping of the wire for several reasons, the most important being the fact that with straight wire the flexing of the same in use is unduly concentrated at the point where the wire leaves the brush back, resuiting in early fracture and greatly reduced life of the brush. when a .crimped wire brush is ground or dressed to afford an even brush face, however, such iace fails to remain even in use but soon becomes irregular due to lengthening or stretching of the crimped wires. A straight wire brush, or moreespecially a brush comprising a mixture of straight wire and Tampico fiber, forexample, mayon the contrary be ground to an even face and desired brush diameter and will maintain such even face for a much longer period in use. Treatment in accordance with my invention serves the very important function of dampening vibration of the wires, thereby greatly prolonging the efiective life of the brush. Such treatment may also protect the wire from corrosion and consequent early fracture due to cor- 2,sss,se7

rcsion embrittlement and concentrations of stress at points of greatest corrosion. 7

When brush material (e. g. Tampico fiber) is treated with a treating fluid aiiording a high degree of permanence of fixation of the bristles, a brush may be provided in which only the outer ends of the bristles pull apart in use, the remainder of the brush material being stifliy bound together. Such a brush will therefore have the characteristics of a short trim brush but will be capable of prolonged use since there is a large body of brush material available as the ends of the bristles wear back. As the bristles wear they progressively loosen and a brush may thus be provided which always presents bristles of an effective length of, say, one-half inch or less. Even in such cases, as above pointed out, the

treating or binding material should not become brittle but retain a degree of plasticity.

While abrasive may be incorporated with the treating material, it is generally preferred to apabrasive material from a container or hopper.

Illustrative examples of typical abrasives which may be used with brushes treated in accordance with my invention are as follows: emery, silica,

silicon carbide, alumina and othersimila'r well known abrasives bound or associated in the form of a more or less firm paste, or in a semi-fluid form, as by suspending in such media as tallow, suitable grease oil, soap}. soluble oil, or glue. Binding media having tackiness suflicient to hold the abrasive or assist in holding it fast to the brush material are preferred. Of the materials meeting the above specifications, those which are also most easily removed by established cleaning methods are preferred.

A convenient method of treating the brush material is to mount the rotary brush sections on a mandrel or spindle, preferably arranged in a vertical position, and immerse the same in a tank containing the selected material. The sections are so placed on the spindle with suitable spacers that the impregnating material will flow into and about the brush fibers and thoroughly wet them.

The spindle and brushes may then be withdrawn above the level of the treating material in the tank and rotated to remove excess treating material may be applied to the brush material before feeding the latter into a machine of the type described in Bickel Patent No. 1,963,045. The bristles of a helically wound brush so treated are maintained in desired position without undue shifting or compacting and will form a uniform brush face.

It will be seen from the foregoing that the objects of my invention have all been achieved in a simple and relatively inexpensive manner, which at the same time results in increasing the usefulness of the brushes, a considerable saving of abrasive, and increased life of the brush m a terial. This in addition to greatly improved operating efiiciency of the brush in use.

Other modes of applying the principle of my invention may be employed instead of the one explained, change being made as regards the structure herein disclosed, provided the means stated by any of the following claims or the claim as my invention:

1. A rotary brush comprising an annular brush back and .brush material extending radially therefrom, such material comprising bristles terial by centrifugal action, such excess material impinging on the sides of the tank and flowing down to rejoin the body of the same. ii'he same general method of treatment is also applicable to helically wound brushes or the treating macoatedv with a tacky fluid of the type which wets such bristles, whereby when the brush is rotated lateral compacting of the outer portions of such bristles is. resisted.

2. An annular rotary brush having fllamental brushing material coated with a tacky substance effective to limit axial compacting of said material in use while assisting in the formation of a firm brush face, said filamental brushing material nevertheless retaining its ability to separate during normal operation in engagement with a work piece.

3. A rotary brush comprising an annular brush back and brush material extending radially therefrom, such material comprising bristles coated with a tacky fluid of the type which wets such bristles, whereby when the brush is rotated the inner portions of such bristles tend to adhere together and lateral compacting of outer portions thereof is minimized.

4. In a method of treating brush bristles for use in rotary and like brushes, the steps which consist in app in to such bristles a viscous tacky substance of the type which wets such bristles, combined with a solvent therefor, and thereupon evaporating such solvent whereby the bristles are left with a coating of such tacky substance.

RUBEN o. PETERSON. 

